diff options
Diffstat (limited to 'target/linux')
| -rw-r--r-- | target/linux/ar71xx/patches-2.6.26/902-mips_clocksource_init_war.patch | 56 |
1 files changed, 38 insertions, 18 deletions
diff --git a/target/linux/ar71xx/patches-2.6.26/902-mips_clocksource_init_war.patch b/target/linux/ar71xx/patches-2.6.26/902-mips_clocksource_init_war.patch index 7c5125f933..bdf0d0fb69 100644 --- a/target/linux/ar71xx/patches-2.6.26/902-mips_clocksource_init_war.patch +++ b/target/linux/ar71xx/patches-2.6.26/902-mips_clocksource_init_war.patch @@ -1,45 +1,65 @@ ---- a/include/asm-mips/hazards.h -+++ b/include/asm-mips/hazards.h -@@ -64,7 +64,7 @@ - _ehb - ) - ASMMACRO(back_to_back_c0_hazard, -- _ehb -+ _ssnop; _ssnop; _ssnop; _ehb - ) - /* - * gcc has a tradition of misscompiling the previous construct using the --- a/arch/mips/kernel/cevt-r4k.c +++ b/arch/mips/kernel/cevt-r4k.c -@@ -187,7 +187,7 @@ +@@ -13,6 +13,22 @@ + #include <asm/smtc_ipi.h> + #include <asm/time.h> + ++/* ++ * Compare interrupt can be routed and latched outside the core, ++ * so a single execution hazard barrier may not be enough to give ++ * it time to clear as seen in the Cause register. 4 time the ++ * pipeline depth seems reasonably conservative, and empirically ++ * works better in configurations with high CPU/bus clock ratios. ++ */ ++ ++#define compare_change_hazard() \ ++ do { \ ++ irq_disable_hazard(); \ ++ irq_disable_hazard(); \ ++ irq_disable_hazard(); \ ++ irq_disable_hazard(); \ ++ } while (0) ++ + static int mips_next_event(unsigned long delta, + struct clock_event_device *evt) + { +@@ -28,6 +44,7 @@ + cnt = read_c0_count(); + cnt += delta; + write_c0_compare(cnt); ++ compare_change_hazard(); + res = ((int)(read_c0_count() - cnt) > 0) ? -ETIME : 0; + #ifdef CONFIG_MIPS_MT_SMTC + evpe(vpflags); +@@ -187,7 +204,7 @@ */ if (c0_compare_int_pending()) { write_c0_compare(read_c0_count()); - irq_disable_hazard(); -+ back_to_back_c0_hazard(); ++ compare_change_hazard(); if (c0_compare_int_pending()) return 0; } -@@ -196,7 +196,7 @@ +@@ -196,7 +213,7 @@ cnt = read_c0_count(); cnt += delta; write_c0_compare(cnt); - irq_disable_hazard(); -+ back_to_back_c0_hazard(); ++ compare_change_hazard(); if ((int)(read_c0_count() - cnt) < 0) break; /* increase delta if the timer was already expired */ -@@ -205,11 +205,12 @@ +@@ -205,11 +222,12 @@ while ((int)(read_c0_count() - cnt) <= 0) ; /* Wait for expiry */ -+ back_to_back_c0_hazard(); ++ compare_change_hazard(); if (!c0_compare_int_pending()) return 0; write_c0_compare(read_c0_count()); - irq_disable_hazard(); -+ back_to_back_c0_hazard(); ++ compare_change_hazard(); if (c0_compare_int_pending()) return 0; |